Vapor removing system for rotary fuel metering devices



Jan- 30, 1951 A. P. scHNAlBLE Erm. 2,539,484

VAPOR REMovING SYSTEM Foa RoTARY FUEL METERING DEVICES ATTo/P/yfv Jan-30, 1951 A. P. scHNAlBLE Erm. 2,539,484

VAPOR REMOVING SYSTEM FoR ROTARY FUEL METERING EvIcEs Filed April 2,1945 2 Shees-Sheet 2 //3 :I i //7 59 //.5 EL., Z5

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ATTORNEY Patented Jan. 30, 1951 VAPOR REMOVING SYSTEM FOR ROTARY FUELMETERING DEVICES Albert P. Schnaible and Willard F. Blakeway, SouthBend, Ind., assignors to Bendix Aviation Corporation, South Bend, Ind.,a corporation of Delaware Application April 2, 1945, Serial No. 586,224

7 Claims. (Cl. 15S-36.4)

This invention relates primarily to fuel-feeding devices of that typewherein the fuel supplied to a power plant or engine is measured ormetered on the basis of engine speed which may be modified by one ormore operating functions or characteristics indicative of mass air flowto the engine, or air consumption. Such adevice is illustrated in thecopending application of Frank C. Mock, Serial No. 586,223, filed ofeven date herewith (common assignee), and now Patent No. 2,531,780granted Nov. 28, 1950.

In fue1-feeding devices of this type, the fuel is conducted underpressure to a chamber embodying rotating parts which tend to impart awhirling motion to theY fuel in the chamber. Such parts in the deviceselected for the purposes of illustration in the present, instancecomprise a pump rotor which draws fuel into the pump chamber, a fuelvalve controlled by a centrifugal governor rotating in synchronism withthe engine, and a cup-shaped member connected to the rotor and having adriving connection with the governor and functioning among other thingsto limit the throw of the governor weights.

In fuel-feeding systems operating on the prin-v ciple of speed meteringpumps, vapor elimination from the fuel passing through the pump chamberand to the engine is essential to accurate metering, and accordingly anobject of the present invention is to provide a vapor elimination systemfor speed metering pumps which is highly effective in operation and atthe same time tends towards simplicity in overall pump construction.

Another object is to generally improve fuelfeeding devices of the typespecified.

The foregoing and other objects and advantages will become apparent inview of the following description taken in conjunction with thedrawings, wherein:

Fig. 1 is a schematic diagram of a speed metering pump in accordancewith the invention;

Fig. 2 is a section taken substantially on the line 2 2, Figure 1; and

Figure 3 is an enlarged section of part of Figure 1.

Referring to the drawings, a main pump housing I has a portion shaped todefine a fuel pump chamber II to which fuel may be supplied from a tankor other suitable source, not shown, through conduit I2. A fuel pump I3has a rotor I4 formed with a center bore mounting a cam pin I5 and aseries of radial slots mounting blades I6. The rotor is supported forrotation in an open sleeve or cage I'l terminating at its opposite endsin rings Ila which cam the blades radially inwardly against the cam pinI5. The right-hand end of the rotor is reduced to provide a drive shaftIda which has a pinion gear I8 secured thereon to facilitate a drivingconnection with the power plant or engine to be supplied With fuel. Thepump I3 takes fuel from chamber II and forces it under pressure intochamber I9 dened by a wall 20- shown as formed integral with the housingI0 and having portions 20a and 20h which are contoured to receive therotor cage Il.

An end cap 2| removably secured to the housing I0 supports the sealingand bearing assembly for shaft Ida to which oil may be supplied throughduct 22.

The left end of the rotor is rotatable in a stepped bearing and sealingring 23 mounted in a boss 24 formed integral with the housing or casingI0, a bushing 25 serving to lock the bearing in place. The left end ofthe rotor is hollow to permit insertion of the cam pin I5, the latterbeing held against endwise displacement by an abutment member 26provided with a sealing ring to prevent escape of fue1 from the rotorbore, said member being removably held in place by a snap ring 21.

The pump rotor I4 has a driving connection with a governor assemblywhich, as will be more fully described hereinafter, is arranged tooperate a poppet valve comprising an elongated valve or valve member 28formed with a reduced stem 28a. The valve member 28 is mounted to slidein a bushing 29 having an attaching flange 29a secured to a flange 30forming part of the wall of an unmetered fuel chamber to be described,said bushing being formed with a valve seat defining a valve port 3 I.

The reduced portion 28a of the valve stem 28 is encircled by a spring 32which at its left end abuts a shoulder formed on the valve stem and atits opposite end bears against the inner race of a thrust bearing 33held in adjusted position by end nut 34, the latter serving to adjustand correlate the governor and poppet valve assemblies.

The governor weights are indicated at 35; they are each secured on ashaft 36 and have formed integrally therewith clutch fingers 3l adaptedto engage the thrust bearing 33 and urge the valve 28 toward openposition, or to the right as viewed@ in Figure l, with a force dependinguponthe speed of rotation and the resulting centrifugal effect of theweights 35. The shafts or pins 36 are anchored in yokes 38 forming partof a' hub 39 carrying the outer races of a bearing assembly 40, theinner races of the bearing assembly being mounted on the bushing 29 andheld in place by endnutor collar 4 I.

A cup or cup-shaped member 42 is secured on the left end of the rotor I4by means of a fitting 43 and'endnutor collar 44;'it functions amongother things to reduce turbulence of the fuel in the chamber I9 and tolimit the throw of the governor weights under certain conditions, as forinstance, when there is no appreciable differential pressure across themetering head diaphragm, to be described. As will be obvious, this cup1*.0- tates with the pump rotor and governor. A fuel baille or shield42a is preferably mounted on the bushing 29 adjacent the valve port 3|;it directs fuel radially from the outer periphery of the governorchamber toward the poppet valve outlet port 3l. This baflie coacts withthe cup 42 to assist in vapor elimination in a manner to be described,and it also reduces turbulence of the fuel in the region of the poppetvalve.

A driving connection between the rotor I4 and governor is provided bymeans of lugs 45 projecting radially from the ange of the hub 39 andengaging in open slots 46 formed in the edge of the cup 42. Thisconstruction tends toward simplicity and it also facilitates assembly.

A governor head diaphragm is indicated at 41, Figure 1; it is clampedbetween the radial portions or flanges of bushings 48 and 49. Bushing 48is slidingly mounted in a guide sleeve 50 supported by hub I, whilebushing 49 has connected thereto a stem 52 adjustably locked in positionby end nut 53. A cable 64 connects at one end with the member 52 and atits opposite end with the stem 28a of valve 28, note Figure 3. A bushing55 steadies the cable 54, and to stiffen the cable sufficiently toprevent buckling due to idle spring thrust, a relatively light wirespring encircles the cable. An idle spring 51 engages the outer side ofthe diaphragm bushing 49 and applies predetermined pressure in anopening direction on the poppet valve 28 at low idling speeds to ensuresuflicient metering head pressure for idling purposes, said spring beingbacked by an end plug 58 which is threaded into end cap 59 and ismaintained in adjusted position by spring-pressed detent members 69.Since the spring 5l may require delicate adjustment, it

is important that the plug 58 be capable of easy adjustment while at thesame time it should be held stable when once set or adjusted; and thedetent members function advantageously in this respect.

A by-pass chamber 6I communicates with the fuel-intake chamber II; andcontrolling passage of fuel from the pressure chamber I9 to the bypass6I is a relief valve 62 which seats on a valve cage 63 mounted in theupper transverse portion of the wall 20 and provided with ports 63a. Thevalve has a depending stem carrying a piston member 65 which slides in avented cylinder 65a, said members 65 and 65a functioning as a dashpot tostabilize the action of the valve 62. A spring 66 is seated in acup-shaped member 61 secured to the valve 62. A diaphragm 68 ofsubstantially the same mean effective area as the seat of valve 62 isclamped between the member 61 and valve 62 and forms a movable wall of abalancing chamber 10. The spring 66 urges valve 62 onto its seat andallows it to open when the pressure in chamber I9 exceeds the pressurein chamber 19 by some predetermined amount dependent upon the strengthof spring 66.

It is important that there be a substantially constant pressure dropacross the valve 26, so that the various pressures in the system arebalanced; also in fuel-feed systems where an injection nozzle is used,the metering needle is rendered less sensitive to variations in nozzlepressure. In the present instance, a constant drop across the valve 26is brought about by connecting the balancing chamber 10 through duct orchannel 1I, 1Ia with unmetered fuel chamber 12 into which the port 3|discharges fuel. The chamber 10 communicates with by-pass chamber 6Ithrough restricted orifice or bleed 16 to permit complete filling ofchamber 10 and to relieve vapor or excess pressure developed in saidchamber by engine heat when the engine is stopped.

When the pump is initially placed in operation and suiicientv pressureis built up in the chamber I9 the valve 62 will open. When this valveopens, fuel is admitted to the chamber 6I, and after this chamber lls,fuel will pass through orice 15 into chamber 10. Since this latterchamber is in communication with the unmetered fuel chamber 12, thepressure on the top side of diaphragm 68 will be metering head pressurewhile that on the lower side of valve 62 will be equivalent to that inthe governor chamber I9, and the differential between these chambers 10and I9 or across the diaphragm and valve assembly 68, 62, and hence thedrop across the valve 28 will therefore be maintained at a substantiallyconstant predetermined value as determined by spring A66, irrespectiveof the volume of fuel delivered by the unit.

The valve indicated at BI, Figure 1, is an idle cut-off valve; it isused to completely cut off flow of fuel to the engine to stop thelatter. The valve is provided with a stem 82 and a lever 83. In theposition shown, the valve is open and fuel may flow through conduit 89,the latter being provided with a coupling member 65 for attachment of asuitable tube or fuel line leading to a spray nozzle, injection pump,burner ring or the like, depending upon what type of power unit is beingsupplied with fuel.

It will be noted that the conduit or duct 1l connects with itscontinuation 1Ia through a valve port 186 controlled by rotary valve 61mounted on and rotatable with valve stem 82 and cut-off valve 8l. Thuswhen the idle cutoff valve is closed, valve 81 is likewise closed andcommunication between the chamber 12 and the chamber 10 is broken. Thereason for this is that should the metering head pressure still obtainin chamber 10 after fuel flow is stopped and during further running ofthe engine due to momentum, the by-pass valve 62 would require so muchpressure to unseat it as to produce dangerously high, pressures in thechamber I9.

A metering needle controls a metering orifice 9| denedby a seat orbushing located in the wall of chamber 12 and communicates said chamberwith a metered fuel chamber 92, from which the fuel flows to dischargeconduit 94. Needle 96 is regulated by an automatic control unitincluding a bellows 93 mounted in a housing 94 defining a chamber 95 towhich charging pressure may be communicated through passage 96. Thebellows 93 maybe evacuated to render it responsive to changes inpressure only, temperature compensation being had through a separatecontrol element, subsequently referred to. An exhaust back pressurecapsule or bellows 91, of reduced size with respect to the bellows |08,coacts with the latter to effect movement of the needle 90 as a functionof manifold pressure modified by a certain increment of exhaust backpressure. The bellows 91 is vented to the atmosphere, since atmosphericpressure may be taken as an index of exhaust back pressure. For a morecomplete description of this automatic control unit, reference may behad to the copending application of Frank C. Mock, heretoforeidentified.

A variable pressure regulator control chamber 98 is in pressurecommunication with the one side of the diaphragm 41 and in restrictedfiow communication with the chamber 12 by means of orice or bleed 99. Acontrol orifice is indicated at it communicates chamber 98 withdischarge chamber 92 through channels |0| and IOI'. A needle |02regulates the area of orifice or bleed |00, said needle being adaptedfor either manual or automatic control, depending upon the type ofengine or power plant to `which fuel is being supplied.

Assuming that the fuel-feeding system is to be used to supply fuel tothe throttle-controlled airintake passage of van internal combustionengine, metering or feed of fuel is regulated by correlating certainvariable factors of engine operation, namely, engine speed or R. P. M.,manifold or boost pressure modified by a certain predeterminedpercentage of exhaust back pressure, for example one-sixth, and manifoldtemperature, to fulfill the following formula:

Fuel flowmanifold pressure-% back pressure manifold temperature XSPeedand driven thereby. Rotation of the pump rotor I4 causes fuel to bedrawn in through conduit I2 from a suitable source of supply, such as aconventional fuel tank, and into the chamber I I, from which it isforced by the rotor blades or varies into the chamber I9. The reliefvalve 82 is set to maintain the fuel in chamber I9 at a predeterminedpressure, over and above the pressure in unmetered fuel chamber 12. Whenthis pressure is exceeded, the excess fuel is by-passed back to thechamber I| through the passage or chamber 6 I.

When the engine is operating, the rotating governor weights and the idlespring 51 tend to open the valve 28 and fuel under pressure is passedthrough orifice 3| into unmetered fuel chamber 12. The fuel iiowsthrough metering orifice 9| into metered fuel chamber 92 and throug-hconduit 84 to a fuel discharge nozzle for supplying fuel to an internalcombustion engine, or burner for a gas turbine or jet propulsionengine'as the case may be. A small portion of the fuel fiows fromchamber 12 through destriction 99 into regulator control chamber 98,thence through the variable orifice, |00 into metered fuel chamber 92and then through conduit 84 to the nozzle along with the fuel flowingthrough metering orifice 9 It will be apparent that the pressure in thevariable pressure regulator control chamber 98 will be of a valueintermediate the unmetered fuel pressure in chamber 12 and the meteredfuel pressure in chamber 92, and will tend to approach the pressure inchamber 12 as the effective area of orifice |00 is decreased by valve|02 and will tend to approach the pressure in chamber 92 as theeffective area of orifice |00 is increased. For a given position ofvalve |02 the differential between the pressures in chambers 12 and 98will remain a constant percentage of the differential between thepressures in chambers 12 and 92, the latter differential being themetering differential pressure effective across the metering orifice 9|.As the valve 28 opens or closes the fuel flow to the nozzle will tend toincrease or decrease and the governor head and the metering differentialwill likewise increase or decrease. The governor head, thatis, thedifferential between the pressures in chambers 12 and 98, is effectiveon the governor head diaphragm 41 tending to move the diaphragm to theleft and tending through cable 54 to move the valve 28 to the left inopposition to the force thereon of the governor weights '35.

The valve 28 will float toward open or closed position until thegovernor head acting on diaphragm 41 balances the force of the governorweights 35. Since the governor rotates in direct relation to engine`speed, the thrust of the governor weights is proportional to speedsquared and therefore the balancing differential across diaphragm 41 ismaintained proportional to speed squared and the metering head acrossthe metering orifice 92 is also maintained proportional to speedsquared. Assuming that the area of the metering orifice 9| is fixed,then flow therethrough would be proportional to the square root ofthe-pressure differential thereacross and hence proportional to enginespeed. For a constant condition of manifold pressure and exhaust backpressure, theair flow to the engine will vary in direct proportion tothe engine speed, and the control mechanism just described willcorrespondingly vary the quantity of fuel supplied to the engine orburner.

The mass rate of air now to the engine in addition to being dependentupon the engine speed is also dependent upon the manifold orl chargingpressure modified by a predetermined increment or portion of the exhaustback pressure. In order to correspondingly vary the fuel fiow withchanges in air iiow resulting from changes in manifold pressure orexhaust back pressure, the area of orifice 9| is controlled by theneedle 90 and the latter is actuated in direct relation to manifoldpressure modified by a predetermined increment of back pressure oratmospheric pressure. Thus as manifold pressure is varied, as byactuation of a throttle valve in the air-intake conduit of aninternal-combustion engine or by variation in speed of a supercharger ata given throttle opening, such variations in pressure will betransmitted to the chamber 95 and imposed on the bellows 93. Thepressure in this chamber 95 also acts on the back pressure bellows 91which is internally vented to atmosphere or to the exhaust manifold andtherefore modifies the travel of the bellows 93 in direct relation tochanges in atmospheric pressure. The travel of the bellows and thecontour of the needle are correlated to obtain the desired fuel orificeareas through the metering range.

Variation in the position of needle |02 will result in a givenpercentage change in the fuel supplied to the engine throughout therange of engine operation. Valve |02 therefore is well suited as amanifold temperature compensating device. For example, a neutral orintermediate control position of needle |02 may be taken at a pointwhere the respective areas of the orifices 99 and |00 are equal and thepressure drops across each orifice are equal. Under. these conditionsthe difference in pressure between chambers 12 and 98 and hence thedifferential across diaphragm 41 is represented by the drop across orice99 and is substantially equal to one-half of the total drop acrossorifices 99 and |00, the total drop being the metering differentialacross metering orice 9|. The differential across diaphragm 41 willretain this one-half relationship at all values of the fuel meteringdifferential or metering orice areas. If now at a given governor orengine speed and a given area of metering orifice 9|, the area of orice|00 is increased as by raising the needle |02, thereby reducing thepressure in chamber 98, the differential across diaphragm 41 may, forexample, become equal to six-tenths of the metering differentialpressure instead of one-half. The differential across diaphragm 41 isthen too large for balancing the force of the governor weights on valve28 and the valve will partially close and decrease the fuel ow until thedifferential across diaphragm 41 is reduced one-sixth, to its formervalue, with a corresponding percentage reduction in the meteringdiierential across the orifice 9|. The quantity of fuel being deliveredthrough orifice 9| to the engine or burner will accordingly be reducedto approximately the square root of vesixths of its former value, andthis percentage reduction in flow through orifice 9| will be effectivethroughout the range of engine speeds and settings of needle |02. On theother hand, if the area of orifice is reduced as by lowering the needle|02, the pressure in chamber 98 will increase and the differentialpressure across diaphragm 41 will decrease correspondingly. The

Aweights 35 will open the valve 28 an additional amount to increase thefuel now until the differential pressure across diaphragm 41 is restoredto its former value to balance the force of weights 35. This will resultin a percentage increase in the fuel ow through metering orice 9|, whichpercentage enrichment will obtain throughout the range of engineoperation. Thus when the area of orifice |00 is at a maximum, the rateof fuel ow will be at a minimum, and when the area of said orifice is ata minimum, the rate of fuel flow will be at a maximum, for any givenengine speed and a fixed position of needle |02. The pressure in chamber98 thus may be selectively varied by needle |02 to accomplish anincrease or decrease in the fuel metering differential pressure relativeto the differential pressure across the governor head diaphragm, whichin turn is maintained in balance with the force of the governor weights35 by means of the valve 28 which opens or closes to increase ordecrease the fuel flow until this balance is established. I

It is important that vapor be completely eliminated from the pressurechamber in which the governor and poppet valve assembly operate. Sincefuel in vapor form is lighter than when in the liquid phase, it tends togather in the central area of the governor chamber (due to the fact thatthe heavier liquid fuel is thrown outwardly by centrifugal force), whereit (the lighter vapor) affects the buoyant action of the fuel on thegovernor weights and increases the effective throw of the latter,thereby increasing the meteringhead and tending toward a rich fuel/airratio. If suicient vapor collects to more than ll the spinning cup andthe governor chamber, it will pass through the system and result in alean condition of the fuel/air ratio. Thus, as in other fuel systems,vapor formation tends towards unstable general.

In the present instance, a vapor elimination system is provided whichtakes advantage of the tendency of the vapor to centrifuge or movetowards the central area of the governor chamber. The spinning cup 42which houses the governor weights 35 is formed with a series of holes oropenings |05 in the peripheral and end walls thereof, and the hub member39 is also preferably formed with a series of openings |08, note Figure3. The abutment member 26 in the end of the rotor |4 is formed withvapor escape openings I01through which vapor passes and thence throughthe space around the abutment member to discharge passages |08 formed inthe rotor and extending on through the bearing 33 and terminating in anannular collecting chamber |09 formed in the boss 24. A vapor ventchannel ||0 communicates the annular chamber |09 with a vapor ventchamber the latter being provided with a float l2 movable vertically inan inverted cup-like guide member ||3 and carrying a valve member |4slidably on the lower end of a hollow depending stem providedwith a port5, said valve ||4 controlling vapor discharge passage IIB, which maylead to a fuel tank, not shown, or to some other suitable point such asan air-intake conduit. The guide member ||3 is apertured as at ||1 toprevent entrapment of air or vapor therein.

The venting system operates as follows:

During periods of operation, a continuous flow of liquid fuel and/orvapor occurs from the centra] portion of the governor chamber throughports |01, |08, annular collecting chamber |09 and passage ||0 to thefloat chamber In the absence of vapor, the liquid fuel entering chamberlls the chamber and the oat valve ||4 closes port ||5. Fuel thereaftersupplied to chamber escapes through passage ||1 and restriction ||8 tothe by-pass chamber 6| which communicates with the pump inlet chamberAny vapor resulting from low pressures, agitation or other causes whichenters or is formed in the chamber I9 will, due to centrifugal action,move inwardly through the holes |05, |06 in the wall of the cup 42 andthe hub 39 and also through the space between the forward edge of thecup and said hub; and this vapor will converge around the axis of thegovernor and valve assembly and thence pass through the holes |01 in theabutment member 26 and outwardly through the channels or vents 08,annular chamber |09 and channel ||0 to the float chamber The baille 42aensures that only the heavy liquid fuel from the periphery of thegovernor chamber reaches the valve port 3| and thus facilitatescentrifuge of the fuel in the governor chamber.

Normally, when there is little or no vapor or air in the float chamberthe valve port ||5 is held closed by the valve ||4; but when vapor orair enters said chamber, it depresses the liquid fuel level, the floatdrops and the valve ||4 uncovers port H5, permitting the vapor and airto escape back to the fuel tank through conduit H6. As the vaporescapes, liquid fuel entering chamber raises the fuel level therein andmoves the oat upwardly to close port I5.

The cupI42 is not essential to effective operation of the ventingsystem; it does however provide a convenient means for limiting thethrow oi' the governor weights and lt also has a quies andunsatisfactory operation in cent action on the fuel in the region of thespinning weights.

With a vapor elimination system as herein disclosed, it is practicallyimpossible to completely vapor-lock the pump for pressurizing the fuel,and hence if the system is used on high-altitude aircraft, fuel tankpressurization or boost pump equipment in addition to the pump I4 maynot be needed. Vapor-lock in conventional pumps is usually caused byslugs of air being carried around by the Pump vanes, and if thesecontinue to accumulate without being passed off, the pump lockscompletely or becomes inoperative to pressurlze the fuel. With thepresent invention, however, air and vapor is discharged on the highpressure side of the pump and does not have a chance to circulate backthrough the relief valve to the inlet side of the pump.

Obviously, the vapor elimination system will operate in any fuelmetering device where the fuel is centrifuged due to a whirling actionor movement irrespective of the particular means which causes suchmovement; hence the inventive concept is not limited to any specifictype of fuel-feeding or charge-forming device or parts thereof but onlyby the scope of the appended claims.

We claim:

1. In a fuel-feeding system for an engine wherein fuel is metered as afunction of engine speed, a fuel conduit having a regulating valvetherein and a govenror operatively connected to said valve, means forrotating said governor in synchronism with the engine including a memberlocated axially of the conduit and a bearing in which said member ismounted; rotation of the governor imparting a whirling action to thefuel and centrifuging the heavier constituents of the fuel towardtheiperiphery of the conduit and the lighter constituents includingvapor inwardducting fuel under pressure to said chamber, a a

metering orifice in said conduit, a valve controlling ilow of fuelfromsaid chamber to said orifice, a centrifugal governor mounted in saidchamber and operatively connected to said valve,

means for rotating said governor in synchronism with the engine,rotation of the governor imparting a whirling action to the fuel andcentrifuging the heavier constituents of the f'uel toward the peripheryof the conduit and the lighter constituents including vapor inwardlytoward the axial portion of the chamber, a vaporcollecting chambex`having a float-controlled valve therein permitting escape of vapor underpredetermined pressure from said latter chamber, and a conduit forconducting fuel and entrained vapor from the axial portion of thegovernor chamber to said vapor-collecting chamber.

3. For use in a fuel-feeding system for an engine wherein fuel ismetered as a function of engine speed, a metering device provided with agovernor chamber, a fuel pump including a pump rotor mounted in saidchamber, a valve controlling flow of fuel from said chamber, acentrifugal governor mounted in said chamber and having an operativeconnection with said valve,

means providing a driving connection between the rotor and governdr,rotation of the rotor and governor imparting a whirling action to thefuel and centrifuging the heavier constituents of the fuel toward` theperiphery of the chamber and the lighter constituents including vaporinwardly toward the axial portion of the chamber, a vapor-collectingchamber, said rotor being provided with an axial passage adapted toreceive fuel and entrained Vapor, and a vapor-removing conduitcommunicating said passage with said vapor-collecting chamber.

4. A pump as claimed in claim 3, wherein said rotor is mounted in abearing having an annular collecting chamber communicating with saidaxial passage through ducts formed in the rotor and said vapor-removingconduit communicates at its intake end with said annular chamber.

5. For use in a fuel-feeding system for anfengine wherein fuel ismetered as a function of engine speed, a metering device provided with apressure chamber, a fuel pump including a rotor mounted in said chamber,a valve controlling flow of fuel from said chamber, a centrifugalgovernor having governor weights mounted in said chamber, said` governorhaving an operative connection with said valve and a driving connectionwith said rotor, a cup-shaped member rotatable with and surrounding thegovernor weights and limiting the throw of the latter, rotation of therotor and governor imparting a. whirling action to thev fuel andcentrifuging the heavier constituents of the fuel toward the peripheryof the chamber and the lighter constituents including vapor inwardlytoward the axial portion of the chamber, a vapor-collecting chamber,said cup-shaped member having a plurality of holes in the Wall thereofto expedite flow of vapor toward the axis of the governor chamber andsaid rotor having an axial passage adapted to receive fuel and entrainedvapor. and a vapor-removing conduit communicating said axial passagewith said vapor-collecting chamber.

6. For use in a fuel-feeding system for an engine wherein fuel ismetered as a function of engine speed, a metering device provided with apressure chamber, a by-pass and a relief valve controlling passage offuel from the pressure chamber to the by-pass, a. metering orificedownstream of said pressure chamber, a valve port and a fuel valvecontrolling flow of fuel from the pressure chamber to said orificethrough said port, a fuel pump including a rotor mounted in saidpressure chamber, a centrifugal governor having governor weightsoperatively connected to said valve, a baille disposed between thegovernor and valve port functioning to ldirect the fuel radially of thepressure chamber prior to passing through said port, a cup-shaped membersurrounding the governor to limit the throw thereof, said latter memberalso providing a driving connection between the rotor and governor,rotation of the rotor and governor imparting a whirling action to thefuel and centrifuging the heavier constituents of the fuel toward theperiphery oi' the pressure chamber and the lighter constituentsincluding vapor inwardly toward the axial portion of the chamber, avaporcollecting chamber, a float valve controlling escape of vapor fromsaid latter chamber, a. vapor-removing passage communicating at itsinlet with the axial portion of said pressure chamber and at its outletwith the vapor-collecting chamber to conduct fuel and entrained vaporfrom said pressure chamber` to said vapor-collecting chamber, and arestricted ow passage communicating the vapor-collecting chamber withsaid by-pass to maintain the liquid fuel in said latter chamber at apredetermined level.

'1. In a fuel feeding system for an engine, a'

fuel conduit having a metering restriction therein, means for creatingnow of liquid fuel through the conduit, a valve for controlling the rateof ow through said restriction, rotatable governor means in said conduitfor controlling said valve, said governor means also acting to impart awhirling action to the fuel during its flow through that portion of theconduit in which the governor means is located, a vapor collectingchamber exterior of said conduit, and a duct having its inlet endlocated to receive the lighter constituents of the whirling body of fueland its discharge end communicating with said chamber.

ALBERT P. SCHNAIBLE.

WILLARD F. BLAKEWAY.

12 REFERENCES CITED The following references are of record in the le ofthis patent# UNITED STATES PATENTS Number Name Date 1,345,895 SegvinJuly 6, 1920 1,906,334 Rathbun May 2, 1933 2,238,502 Muir et al. Apr.15, 1941 2,275,355 Finken Mar. 3, 1942 2,368,528 Edwards Jan. 30, 19452,368,529 Edwards Jan. 30, 1945 2,368,530 Edwards Jan. 30, 19452,412,289 Pugh et al. Dec. 10, 1946 FOREIGN PATENTS Number Country Date526,988 Great Britain Sept. 30, 1940 630,932 Germany June 9, 1936

